Born in 1916, she married in 1953 and worked as a journalist, a teacher, and at the BBC. In 1975, she published her first book, a biography of Victorian painter Edward Burne-Jones. In 1979 she won the Booker Prize for her third novel Offshore, which was roughly based on her experiences living on a boat on the Thames. She continued to write nine novels, including The Blue Flower, for which she won the Critics Circle prize in 1998, three biographies, and a collection of short stories published after her death.

Fitzgerald's writing is often very straightforward, but she manages to convey a great deal in her terse sentences. Much of her writing is autobiographical, and she is able to capture the nuances of daily life on the Thames, at the BBC, or working in a bookshop. She seems most interested in telling the stories of lives; when not her own, those of the people she admires: The Blue Flower is based on the slightly bizarre life of the Romantic poet Friedrich von Hardenberg, better known as Novalis.